Power line communication (PLC), also called mains communication, power line transmission, or power line networking (PLN), is a communication technology which uses existing power distribution cables for transmitting data. Modulated carriers are impressed on the standard 50 Hz or 60 Hz alternating current. High-frequency power line communication uses carrier frequencies up to 30 MHz and more. Power line communication can for example be used in a home to interconnect computers and peripherals and home entertainment devices. Power line modems intended for home use, also called power line stations or power line adapters, typically plug into power outlets and establish a high-speed data connection using the existing electrical wiring in the home. A power line modem may also be integrated within an electronic device to allow connection of the electronic device to a local network.
Digital subscriber line (DSL) denotes a family of technologies (ADSL, VDSL, VDSL2) that provide high-speed digital communications by transmitting digital data over the wires of a local telephone network. DSL is typically used to connect households to the Internet. Today, VDSL2 modems modulate frequencies up to 30 MHz.
Power line communication (PLC) might interfere with digital subscriber line (DSL) communication. The publication ETSI TR 102 930; “PowerLine Telecommunications (PLT); Study on signal processing improving the coexistence of VDSL2 and PLT”; ETSI 2010; suggests methods to reduce or mitigate the crosstalk between electricity and telephone cables. The disclosed methods are based on an adaptive interference cancelling filter and spectral management.
Today, PLC modems use the frequency range above 30 MHz only with a very limited power spectral density (PSD). However, in order to achieve higher data rates or coverage, it is envisaged to enable higher feeding limits for PLC in those frequencies. In this case there is a high potential to observe interferences from PLC to frequency modulated (FM) radio broadcast.
The publication ETSI TS 105 578; Power line Telecommunications; “Coexistence between PLT modems and short wave radio broadcasting services”; ETSI 2008; describes an adaptive frequency notching technique, which on the one hand has a minimum impact on data throughput and QoS (Quality of Service) requirements and, on the other hand refuses interference between PLT (Power line telecommunications) and short wave radio broadcast.
There is a need to improve power line communication modems and digital subscriber line modems to reduce effects of crosstalk with interfering technologies.